Strawberry mulching time is almost here

Mild fall weather has delayed mulching for most strawberry growers.

For the last month, strawberry growers have been asking if it is time to apply straw mulch as the weather this fall has continued to be mild. I have encouraged growers to hold off for colder weather. Strawberry mulch is typically spread after plants are exposed to several nights with temperatures in the lower 20s. For most of Michigan, this occurs in mid-November, but this year (2012) plants have continued to grow much later than normal.

Michigan State University Extension’s best response to strawberry growers when asked the question as to the best time to apply straw mulch is to let your plants tell you the right time. After several hard frosts, you will see the leaves turn red; this is not the time for mulch application. The next step in the hardening process you will see the leaves begin to collapse into the crown or to fall over, and finally the leaves will flatten completely to the ground. This last step of leaf flattening is the right timing for mulch application.

Plants mulched too early in the fall do not harden off well or get ready for winter properly. Research has shown that delaying mulch application till just before the ground freezes will result in the highest yields the following season. On a practical side, I know that growers want to get the mulching finished up before the weather turns nasty or before fields become too wet.

Straw mulch primarily serves to protect the plant from cold injury during the coldest parts of winter and reduces the freeze or thaw cycles that are typical in most Michigan winters. The mulch also helps to reduce fruit diseases at harvest time by reducing splashing of soil particles that carry diseases onto the berries.

Remember to make that one last application of a herbicide to help with weed control in the spring and early summer. For more details on fall herbicide selection, refer to Dr. Bernie Zandstra’s article, Fall weed control on asparagus, rhubarbs and strawberries.